Acts 15:36-39 NLT

36 After some time Paul said to Barnabas, "Let's return to each city where we previously preached the word of the Lord, to see how the new believers are getting along."
37 Barnabas agreed and wanted to take along John Mark.
38 But Paul disagreed strongly, since John Mark had deserted them in Pamphylia and had not shared in their work.
39 Their disagreement over this was so sharp that they separated. Barnabas took John Mark with him and sailed for Cyprus.